<h4>Tool</h4><table border="0"><tr><td valign="top"><b>Name</b></td><td valign="top">Wombling (Edge Detection)</td></tr><tr><td valign="top"><b>ID</b></td><td valign="top">16</td></tr><tr><td valign="top"><b>Author</b></td><td valign="top">O.Conrad (c) 2015</td></tr><tr><td valign="top"><b>Specification</b></td><td valign="top">grid</td></tr></table><hr><h4>Description</h4>Continuous Wombling for edge detection. Uses magnitude of gradient to detect edges between adjacent cells. Edge segments connect such edges, when the difference of their gradient directions is below given threshold.

References:
- Fitzpatrick, M.C., Preisser, E.L., Porter, A., Elkinton, J., Waller, L.A., Carlin, B.P., Ellison, A.M. (2010): Ecological boundary detection using Bayesian areal wombling. Ecology 91(12): 3448-3455. doi:10.1890/10-0807.1
- Fortin, M.-J. and Dale, M.R.T (2005): Spatial Analysis - A Guide for Ecologists. Cambridge University Press.
<hr><h4>Parameters</h4><table border="1" width="100%" valign="top" cellpadding="5" rules="all"><tr><th>Name</th><th>Type</th><th>Identifier</th><th>Description</th><th>Constraints</th></tr>
<tr><th colspan="5">Input</th></tr><tr><td>Feature </td><td>Grid (input)</td><td>FEATURE</td><td></td><td></td></tr><tr><th colspan="5">Output</th></tr><tr><td>Edge Points (*)</td><td>Shapes (optional output)</td><td>EDGE_POINTS</td><td></td><td></td></tr><tr><td>Edge Segments (*)</td><td>Shapes (optional output)</td><td>EDGE_LINES</td><td></td><td></td></tr><tr><td>Gradients (*)</td><td>Grid list (optional output)</td><td>GRADIENTS</td><td></td><td></td></tr><tr><th colspan="5">Options</th></tr><tr><td>Minimum Magnitude</td><td>Floating point</td><td>TMAGNITUDE</td><td>Minimum magnitude as percentile.</td><td>Minimum: 0.000000
Maximum: 100.000000
Default: 90.000000</td></tr><tr><td>Maximum Angle</td><td>Floating point</td><td>TDIRECTION</td><td>Maximum angular difference as degree between adjacent segment points.</td><td>Minimum: 0.000000
Maximum: 180.000000
Default: 30.000000</td></tr><tr><td>Minimum Neighbours</td><td>Integer</td><td>TNEIGHBOUR</td><td>Minimum number of neighbouring potential edge cells with similar direction.</td><td>Minimum: 0
Default: 1</td></tr><tr><td>Alignment</td><td>Choice</td><td>ALIGNMENT</td><td></td><td>Available Choices:
[0] between cells
[1] on cell
Default: 1</td></tr><tr><td>Edge Connectivity</td><td>Choice</td><td>NEIGHBOUR</td><td></td><td>Available Choices:
[0] Rooke's case
[1] Queen's case
Default: 1</td></tr><tr><td>Output of Gradients</td><td>Boolean</td><td>GRADIENTS_OUT</td><td></td><td>Default: 0</td></tr></table>(*) <i>optional</i>